1. Field of the Invention
This invention relates generally to devices for sealing a substance within a syringe and particularly to capping and stopping means.
2. Prior Art
Two devices have long been used to seal a syringe which contains a sample which must be kept free from contamination and prevented from escaping the syringe. The first device is a simple solid frustoconical shaped stopper made of rubber, plastic or other material which may be easily pierced by a cannula. The cannula is inserted into the stopper a distance sufficient to insure that it is secure therein and that the cannula is sealed. The second device is a cap. The cap is used to seal the open end of the syringe after the cannula assembly has been removed. The cap is typically made of an elastic material which must be somewhat stretched to fit over the end of the syringe. Pertinent Prior Art patents include U.S. Pat. No. 3,098,481 to Wikander et al and U.S. Pat. No. 3,380,452 to Elias.
Kits or trays are in common usage in conjunction with the collection of samples by syringe. Such kits must contain both a cap and a stopper since very often the preference for the specific sealing means is not readily discernable in advance. This means that the kit or tray must have space for both sealing means, and both sealing means must be kept in inventory.
The typical stopper is a solid conical section having two flat parallel ends which are perpendicular to the main axis of the conical section, i.e. frustoconical. Such stoppers, having all rounded sides, are difficult to hold and thus the cannula is often inserted at an improper angle which may result in the cannula puncturing a finger of the technician.
The typical cap is rather small, having a diameter not much larger than the outer diameter of the cylindrical portion of the syringe. The cap is therefore somewhat difficult to hold and place over the end of the syringe and in any event will trap air in the syringe thereby contaminating the sample contained therein.
It is therefor an object of the present invention to provide a cap and stopper of unitary construction thereby eliminating the necessity of providing space on the tray for a cap and another space for a stopper; and also eliminating the necessity of keeping both caps and stoppers in inventory.
It is another object to provide an improved cap and stopper as above having relatively large flat surfaces so as to provide for improved gripping and so as to prevent the device from rolling about on a tabletop or other flat surface when accidentally (or purposefully) impacted.
It is a further object of the present invention to provide an improved cap and stopper which has a target area on the stopper portion to aid in proper selection of a location to insert the cannula.
A further object of this invention is to provide a cap which will allow air to be expelled from the cap during the capping process rather than compress air from the cap into the syringe thereby contaminating the sample.
Another object of this invention is to provide a cap of a material sufficiently soft and flexible such that the cap will properly seal the end of the syringe whether it is a threaded end or a tapered end without threads.